Value is multifaceted, but in this case it should be pretty clear. If the demand for something only exists at a price less than the cost of production, then the product will not appear on the market (at equilibrium, all else being equal, etc.). If something costs you zero to make, the price of the item will probably fall to zero (at equilibrium, all else being equal, etc.), regardless of demand. A crappy statue has multiple valuations, one of which is the cost of production (in addition to use value, exchange value, market value, labor value, etc.).
Treating labor as a commodity is by definition dehumanizing. Dehumanization “entails a perception of other people as nonhumans — as statistics, commodities, or interchangeable pieces in a vast ‘numbers game’. Its predominant emotional tone is that of indifference ... together with a sense of noninvolvement in the actual or foreseeable vicissitudes of others” (Bernard, Ottenberg, and Redl 1971, 105-6). Even in cases of slavery, the slave's labor is not what is actually considered the commodity. Commodification of labor has lead to real declines in the US and abroad in terms of worker quality of life, wage stability, worker freedom, power relations, worker skills, and democratic involvement.